Azo dyestuffs



' Patented Jan. 14, 1941 Azo DYESTUFFS Ernst Messmer, Leverkusen I. G. Werk, Rhine, Germany, assignor to General Aniline & Film Corporation, a corporation of Delaware No Drawing. Application February 25, 1938, Serial No. 192,566. InGermany March 4, 1937 5 Claims. (01. 269-178) The present invention relates to new azo dyestuffs and to methods of preparing the same, more particularly it relates to azo dyestuffs which maybe represented bythe following gen- 5 eral formula: :I

In this formula R stands for the radical of an aromatic o-hydroxy-carboxylic acid and R1 stands for the radical of a coupling component which bears ahydroxy group in a position adjacent to the azo-group and which may contain azo-groups. l

My new dyestuffs are obtainableby combining the tetrazo compounds prepared from aminobenzoylphenylendiamine o carboxylic acids of 2 the constitution:

HZN CO.NH l N---N or their nuclear substitution products andby combining these diazo-oompounds with an'o-hydroxycarboxylic acid capable of coupling. They are prepared, for instance, by combining diazotized nitroor acylamino -o-aminocarboxylic acids of the benzene series with an azo component coupling in a position, adjacent to a hydroxy group, and, after reduction of the nitro, group or saponification of the acylamino group, nitrobenzoylating, reducing the 'nitro group, diazotizing and combining with an o-hydroxycarboxylic acid capable of coupling, for instance, with salicylic acid, cresotinic acid, etc.

The dyestufis thus obtainable are soluble in water and go on cellulose and regenerated cellulose, they yield, when aftertreated with agents which gave a metal, dyeings of very good fastness to light and'washing.

Example 1 27.1 parts of -p-aminobenzoyl-Z-phenylencliamine-carboxylic acid are diazotized with 13.8 parts of sodium nitrite with the addition of hydrochloric acid. The solution thus obtained is freed from any impurities by filtration; then the free mineral acid is neutralized with sodium carbonate while cooling with ice and the mixture is stirred with a neutral solution containing 15 parts of salicylic acid and 140 parts of a 20% sodium carbonate solution. After 3 to 4 hours the one-sided coupling is complete. A spot test on filter paper showns a brownish yellow precipitation with colourless outrun, which does not become coloured with an alkaline pnaphthol solution. Then a neutralsolution prepared from,22.4 parts of l-naphtholl-sulphonic acidand 90 parts of a 20% sodium carbonate solution isadded. The following day the dye: stuff thus formed is filtered off. It corresponds in the free state to the following formula:

SOaH

COOH 00011 and dyes cotton bluish red; after-treatment with agents giving copper yields a copper-red dyeing of good fastness to washing and light.

The following table shows shades which can be obtained of the same initial coupling by replacing the l-naphthol--sulphonic acid by other final components; 3 v

- Shade of dyeing Shade of coppered 50 Final component on cotton dyeing l-phenyl-3-methy1-5-pyrazolone A. Orange... .1... Redd ish-yellow. p-Gresol Yellowish-browni. Light reddish-brown. 2-acetamino-5-naphthol-7-sulphonic acid Blu1sh-red Yellowish-Bordcaun 2-phenylamino-5-naphthol-7-sulphon c acid Ruby Garnet. 2-phenylaminc-8-naphthol-6-sulphomc acid Dark brown Yellowish dark brown. 00 Monoazo dyestufi: o-chloraniline, diezotized, coupled man acid medium Greenish-bluenu Bluish green.

with l-amino-8-nephthol-4-sul honic acid. Monoazo dyestufi: 5-nitro-2-am nobenzoio acid, diazotrzed, coupled in an Reddish violet. Dark grey.

acid medium with 2-aminc-5-naphthol-7-sulphon c acld. I 2-p-aminobenzoylamlno-fi-naphtho1-7-sulphonic acid further diazotized Bluish-red H Reddish-brown.

and coupled with salicylic acid.

Example 2 27.1 parts of 5-p-amino-benzoyl-2-phenylenediamine-carboxylic acid are diazotized and coupled with salicylic acid, according to the manner described in Example 1. Then a cold alkaline solution of 21.2 parts of acetoacet-o-chloranilide is added together with 90 parts of a 20 percent pension is cooled to C. and stirred with a solution prepared from 1? parts of o-cresotinic acid with 120 parts of a 20 percent sodium carbonate solution. The coupling product shows properties similar to those of the dyestufi obtained according to Example 1. In the free state it corresponds to the following formula:

COOH OH COOH sodium carbonate solution. After some hours stirring the dyestulf formed is filtered off. It corresponds in its free state to the followinx fo mu a coon 00011 and dyes cotton light lemon-yellow shades, which, when after-coppered, become deeper and very fast to light and washing.

Example 3 The diazoazo compound, prepared in the same way as described in Example 1 is mixed with a v BIO-Q =NGCONHOCOOH OH OCH neutral solution of 23.9 parts of 2-amino-8-naphthol-fi-sulfonic acid and 90 parts of a 20% sodium carbonate solution. The isolated dyestufi corresponds in its free state to the following formula:

COOH 'COOH and dyes cotton dull violetish-brown shades; when aftertreated with copper a brown of good fastness to light and washing is obtained.

Example 4 18.2 parts of 5-nitro-2-aminobenzoic acid are diazotized and coupled with 22.4 parts of l-naphthol-4-sulfonic acid. The dyestuff is reduced to Example 5 27.1 parts of 4-p-aminobenzoyl-Z-phenylendiaminecarboxylic acid are diazotized in the same way as the isomeric compound in Example 1, and

one side is coupled with salicylic acid. After the first coupling is complete a neutral solution of 34.3 parts of 2-benzoylamino-5-naphthol-7-sulphonic acid and 45 parts of a'20 percent sodium carbonate solution are added. The dyestufi thus obtained corresponds in the free state to the following formula:

and dyes cotton reddish orange shades. By after-coppering the dyeing turns somewhat darker, while the fastness to Washing and light are improved. If the final coupling is efiected with 31.5 parts of 2-phenylamino-5-naphthol-7- Hoes N NH

sulphonic acid, a dyestuif is obtained which dyes cotton brownish-red and yields, when after-coppered, a yellowish red which is fast to washing and light.

I claim:

1. Azo dyestuffs of the general formula:

COOH

wherein R stands for the radical of an aromatic o-hydroxy-carboxylic' acid of the benzene series and R1 stands. for the radical of a coupling component bearing a hydroxy group in a position adjacent to the azo-group', yielding on cellulosic fibres, when aftercoppered, dyeings of very good fastness to light and Washing.

COOH

2. A20 dyestufis of the general formula:

0oon wherein R1 stands for the radical of a coupling 3. The azo dyestuff which corresponds in its free state to the following formula:

OHv

dyeing cotton bluish red. shades and yielding, when after-coppered, copper-red shades of good fastness to light and washing.

4. The azo dyestuff which corresponds in its free state to the following formula:

' HO .C

COOH

component bearing a hydroxy group in a position adjacent to the azo group and X means a substituent of the group consisting of hydrogen and O O H alkyl yielding, when aftercoppered dyeings of very good fastness to light and washing.

HOaS

coon

dyeing cotton dull violetish brown shades and yielding, when after-coppered, brown shades of good fastness to light and washing.

ERNST MESSMER. 

